The present invention relates to a new and improved construction of apparatus for transporting continuously arriving or inbound flat paper products, especially a stream of printed products arriving in an imbricated formation.
In its more particular aspects the apparatus for transporting continuously arriving flat paper products of the present development is of the type comprising a guided endless revolvingly driven traction element or means and controlled gripper units or grippers arranged at the traction element at a distance or in spaced relation from each other and adapted to grip one lateral margin or marginal edge of such paper products as seen in the transport or conveying direction thereof.
Apparatus of such general type is known in the art and one essential advantage thereof is that such apparatus does not need to be adapted to the size of the paper products to be transported provided that the lateral margins or marginal edges intended to be gripped of the consecutive paper products are to some extent in alignment with one another. The unilateral or one-sided, lateral gripping of the paper products, on the other hand, results in the same so-to-speak fluttering due to the air flow or travel wind, particularly at higher transport speeds of the products, and thus, causes them to become crumbled or creased. To prevent the undesired crumbling or creasing of the paper products in the known construction of apparatus stationary guiding rails are provided along the entire transport of conveying path for both of the flat sides of the paper products. If it is desired to change the course of the transport path in the state-of-the-art apparatus, it is required to also accommodate the guiding rails in the known apparatus to the new travel course. Significant in this regard is the transport system known as the "KS-Carrier" and described in the brochure of Kaneda Kikai Seisakusho, Ltd.
In a further transporting apparatus as known, for example, from British Pat. No. 752,322, published July 11, 1956, which also acts on one lateral margin or marginal edge of the paper products, it is intended to prevent the transported paper products from fluttering without providing guiding rails. The basic idea in this construction of prior art transporting apparatus is to practically eliminate the flexibility or bendability of the paper products to be transported about bending axes extending parallel relative to the direction of transport. For realizing this basic idea such transporting apparatus is not equipped with gripper units in the narrower sense of this term, but with two rows of disc-shaped entrainment elements arranged with parallel axes and coupled to an endless revolving traction element. The entrainment elements are covered, for example, by rubber at the circumference thereof. The entrainment elements are arranged in such a manner that the entrainment elements of one of the rows is positioned between two entrainment elements of the other rows and are resiliently biased towards the same. For charging this construction of transporting apparatus with paper products the two rows or series of entrainment elements are urged away from each other by appropriate control curves, the paper products are then introduced therebetween and then the entrainment elements are again released. As a consequence, a corrugated or undulatory shape extending transversely with respect to the direction of transport is imposed upon the paper products which results in the desired stiffening. However, since in this known design of transporting apparatus each entrainment element of one of the rows coacts with two entrainment elements of the other row, each of the imposed corrugation waves is fixedly clamped at the leading flank as well as at the trailing flank thereof, so that so-to-speak "breathing", i.e. stretching and/or compressing of the now corrugated shape of the transported paper products, is not readily possible. As a consequence thereof, small relative displacements or shifting movements occur between the entrainment elements, on the one hand, and the paper products, on the other hand, or between adjacent paper products in case the paper products arrive in a stream having an imbricated formation, in such known transporting apparatus when travelling through curves, either in the plane of or transversely with respect to the plane of the paper products. However, such relative displacements or shifting movements are detrimental for the paper products, since either the rubber-covered entrainment elements thus will "grind" or "erase" the paper products and/or there will occur friction between the products lying on top of each other.